Iran's Threat to Close Strait of Hormuz Isn't Entirely Empty

Despite growing calls for President Obama to call Iran's bluff in the Strait of Hormuz, the Islamic republic could credibly close off the waterway, according to military experts speaking to Reuters and The New York Times.

On Thursday, the New York Post'sBenny Avni urged the president to "call the mullahs' bluff" and defy the its warning for the U.S. Navy's aircraft carrier John C. Stennis to stay out of the Gulf. "The Iranian on-again-off-again threat to block the major naval artery, through which a third of the world’s shipped crude oil passes daily, is an empty threat," he said. The proclamation followed a Wednesday Wall Street Journal column by Bradley Russell and Max Boot downplaying Iran's ability to block the strait. "Closing the strait is not nearly as easy as Adm. Habibollah Sayari, commander of the Iranian Navy, would have it," they wrote. "He said that closing the strait is 'as easy as drinking a glass of water.' Actually it would be about as easy as drinking an entire bucket of water in one gulp."

Those columns, however, understate the ease in which the country could seal off the crucial waterway, according to two new reports. According to Reuters, the logistics of closing the 25 mile entrance to the Gulf play to the advantage of a country like Iran, exploiting asymmetrical warfare. "Should Iran's rulers ever make good their threats to block the Straits of Hormuz, they could almost certainly achieve their aim within a matter of hours." Making use of fishing vessels, "smart mines," midget submarines, homing torpedoes, the news service describes a couple plausible scenarios:

Iran is also believed to have built up fleets of perhaps hundreds of small fast attack craft including tiny suicide speedboats, learning from the example of Sri Lanka's Tamil Tiger rebels who used such methods in a war with the government. At worst, its forces could strike simultaneously at multiple ships passing out of the Gulf, leaving a string of burning tankers and perhaps also Western warships.

But a more likely initial scenario, many experts believe, is that it would simply declare a blockade, perhaps fire warning shots at ships and announce it had laid a minefield. "All the Iranians have to do is say they mined the strait and all tanker traffic would cease immediately," says Jon Rosamund, head of the maritime desk at specialist publishers and consultancy IHS Jane's.

The Times also reiterates the country's ability to carry out the mission. "An Iranian blockade by means of mining, airstrikes or sabotage is logistically well within Tehran’s military capabilities," the newspaper reports. This is not to say, however, that Iran doesn't have a huge incentive not to close the strait. By all accounts, a prolonged effort to close the strait would be a losing battle for the Iranian navy and, according to The Times, it would also punish Iran's key ally China, which has heavily invested in Iran's oil fields. Still, the increasing brinkmanship could lead to a military confrontation, analysts say. “I fear we may be blundering toward a crisis nobody wants,” Helima Croft, senior geopolitical strategist at Barclays Capital, tells the newspaper. “There is a peril of engaging in brinksmanship from all sides.”